The Labour Party got closer to the historically blue Selwyn seat this election than it has in 27 years.
National's Nicola Grigg won the seat with 18,578 votes, Labour's Reuben Davidson trailed 4943 votes behind on 13,653.
It is the closest Labour has been to winning the electorate since the 1993 election when Ron Mark lost the seat to National's Ruth Richardson by just 888 votes.
The Selwyn electorate incorporates the district itself, parts of Rakaia and Chertsey.
Davidson posted on his Facebook page about the election results.
"An amazing night for Labour in Selwyn and across New Zealand. Thanks to everyone who helped on our campaign and thanks to everyone who voted for Labour.
"A massive thanks to the Selwyn team who allowed me to be their candidate and worked so hard to get a record result in the electorate," he said.
Grigg will replace Amy Adams who retired from politics at the election, she held the seat since 2008.
Past election results in Selwyn:
• Amy Adams (National) - 28,686
• Tony Condon (Labour) - 9047
• Chrys Horn (Green) - 2772
• Amy Adams (National) - 24,625
• Peter Selwyn Hill (Green) - 4064
• Gordon John Dickson (Labour) - 3835
• Amy Adams (National) - 24,963
• Jo McLean (Labour) - 5512
• Eugenie Sage (Green) - 3674
• Amy Adams (National) - 21,836
• David Coates (Labour) 10,761
• Philippa Main (Progressive) 1316